Draft



Nov, 30, 926.

. 1,608,630 F. B. SNYDER DRAFT APPLIANCE FOR FURNACES Filed June 5, 1926 2 Sheets-Sheet 1 Nov. 30 1926.

F. B. SNYDER DRAFT APPLIANCE FOR FURNACES Filed June 5. 1926 QSneets-Sheet 2 Patented Nov. 30, 1926.

UNITED STATES PATENT OFFICE.

FRANK B. SNYDER, OF LANCASTER, PENNSYLVANIA, ASSIGNOR F FORTY-NINE PER CENT T0 JOHN H. HALLES AND OF FIFTY-ONE PER CENT T0 R. L. PETERMAN, BOTH OF LANCASTER, PENNSYLVANIA.

DRAFT APPLIANCE FOR FURNACES.

Application filed June 3, 1926. Serial No. 113,496.

This invention relates to improvements in draft appliances for furnaces and more particularly to a draft appliance for heating furnaces in which soft coal is to be burned,

and one of the objects of the invention is to provide a draft appliance of such con struction that the products of combustion will be conducted from the furnace in a steady and uniform draft or flow, thus of fecting substantially complete combustion of the fuel and obviating the dense smoke which is usually produced in burning fuel of the character referred to.

Another object of the invention is to so construct the draft appliance that there can be no back draft into the furnace so that the perfect and complete combustion of the fuel will not be interfered with and no gaseous products of combustion or smoke will issue from the furnace to cause annoyance to those residing in the house in which the furnace is installed.

Another object of the invention is to provide means whereby the products of combustion, as they are delivered into the chimney, will be divided into two separate currents and in such a manner as to tend to es tablish a swirling of the currents a short distance above their point of delivery into the chimney flue, thus setting up a constant and uniform draft through the appliance and insuring of more complete and perfect combustion of the fuel.

Another object of the invention is to so construct the device that the delivery of the products of combustion from the burning fuel will be so controlled, automatically, as to insure of even burning of the fuel so that it will be consumed uniformly and the best results thus obtained.

In the accompanyingdrawingsz Figure 1 is a view in side elevation of the appliance embodying the invention installed in connection with a furnace and chimney.

Figure 2 is a vertical transverse sectional view in detail, taken substantially on the line 2-2 of Figure 1, looking in the direction indicated by the arrows.

Figure 3 is a vertical longitudinal sectional View through the flue pipe of the appliance, the damper being shown partly open.

Figure 1 is a Vertical longitudinal sectional view through the baffle section of the appliance.

In the drawings, the numeral 1 indicates in general an ordinary heating furnace and the numeral 2 indicates the ordinary chimmy having the usual flue 3. As is well known, the common practice is to lead a flue of relatively large diameter from the furnace to the chimney and deliver the products of combustion into the flue 3, the delivery or discharge end of the flue pipe being fitted intothe usual opening in the chimney wall and terminating within the opening. I have found, however, that this common practice is disadvantageous where soft coal is to be consumed and that, in fact, even where hard coal is employed, better results may be obtained by a draft appliance constructed in accordance with the present invention and designed to prevent any back draft from the chimney flue. The appliance embodying the invention comprises two units, one being a draft unit and indicated in general by the numeral 4, and the other a bafile unit and indicated in general by the numeral 5. The draft unit 1 comprises a section of flue pipe including a straight length 6, elbows 7 and 8. and a short upwardl extending branch 9 between the elbows. ne end of the portion 6 of the unit 1, namely the end opposite the end at which the elbow 7 is located, is fitted to the thimble 10 which is usually found on heating furnaces, and this unit takes the place of the flue pipe usually fitted to the said thimble. A damper 11 of the ordinary type is mounted in the portion 6 of the draft unit near the elbow 7 and under normal conditions this damper will be left substantially closed although, as is usual, it is provided with two small sized draft openings 12 to provide for a restricted draft.

The damper 11 is, in fact, only employed in full open position when a fresh fire is being built in the furnace and, at other times, will be adjusted to nearly closed position or completely closed position. A draft pipe 13 is arranged to extend from the attached end portion of the part 6 of the draft unit 4 to the back of the elbow 8 and is, therefore. arranged in an upwardly incline-d position and serves to conduct the products of combustion, which do not pass through the main part of the unit, directly to the elbow 8 where they are delivered into one or more lengths of flue piping 1a which, in turn, conduct the products of combustion to the unit 5.

The unit 5 comprises a hollow cylindrical body 15 whichmay be formed from a length of flue piping or may be cast, either as desired, and this body is fitted into a thimble 16 arranged in the usual manner in the flue opening of the chimneywall and ex tends at its inner end into the flue 3, the pipe at its other end being connected with the pipe section 1 1. The body 15, from its free end, is cut away on curved lines, as indicated by the numeral 16, to a point midway between the ends of the body or to such a distance that with the section or body arranged within the chimney in the manner shown in Figure 1 of the drawings, the free end of the body will nearly abut the wall of the chimney flue opposite the wall in which the thimble 16 is arranged, and the lower end of the cut away portion will' be located relatively close to the inner end of the said thimble 16. In this manner, a gradually tapering baffle is provided within the chimney flue, and it will be observed by reference to Figures 1 and 2 of the drawings that the products of'combustion are caused to pass upwardly about the edges 16 of the cut away portion or baflie in the manner shown in the said figures by the arrows and, in passing up through the chimney flue, will follow a circling or swirling course, thus creating a considerable draft in the appliance embodying the invention and effecting thorough and perfect combustion of the fuel in the firebox of the furnace without any likelihoodof any down draft in view of the fact that the ba-flle of the unit 5 extends into the chimney flue and constitutes means for effectually preventing such back draft through the memher 5. In order to prevent any side draft which might interfere with the discharge of the products of combustion from the baffle unit into the chimney flue, and likewise in order to insure of a separation or division of the products of combustion so as to cause substantially the same volume to flow and escape at either side of the baffle, a vane 17 of sheet metal or any other construction is secured at its upper side at one end to the under side of the narrow end of the baflie provided at the end of the body 15, and the inner end of this vane is secured by rivets or otherwise, as at 18, to the lower side of the member 15 at the lower side of'the cut away portion 16, the front and lower edges of the vane 17 extending at right angles to each other as clearly shown in Figure 4, and the upper edge of the said vane being curved downwardly and rearwardly from the attached outer end of the said vane, as indicated by the numeral 19. It will now be evident that the products of combustion will be caused to separate and flow upwardly at opposite sides of the baffle formed by the cut away portion 16 and these upflowing currents will meet above the baffle and a swirling draft will be established in the chimney flue, effectually preventing any back draft which would result in uneven and imperfect consumption of'the fuel in the fireb n of the furnace.

It will be understood, of course, that the units 4 and 5 are to be placed upon the market and it will be evident that they may be readily adapted to any furnace and to any chimney and connected by the ordinary flue piping, of which any desired length may be used.

Having thus described the invention, what I claim is:

1. In a draft appliance for furnaces, a hollow body member for delivering the products of combustion from axfurnace to a chimney having a baffle extending "beyond its discharge end to obstruct back draft from the chimney, and a vane supported beneath the said zbaflie and extending from the outer end of the baffle to the said end of the body at the lower side thereof and providing means for causing division of the products of combustion as they are deflected by the baflie.

2.111 a draft appliance for furnaces, a hollow body member for delivering the products of combustion from a furnace to a chimney having a bafile extending be yond its discharge end to obstruct back draft from the chimney, and a'vane supported beneath the said baffle and extending from the outer end of the battle to the said end of the body at the lower side thereof and providing means for causing divisionof the productsof combustion as they are deflected by the baflle, the upper edge of the said vane 'being inclined downwardly from the front end of the vane to the rear end thereof.

8. In a draft appliance for furnaces, a hollow body member for delivering the products of combustion from a furnace .to a chimney having its lower side cut away on downwardly andoutwardly curving lines whereby to provide a baflie extending beyond the dis-chargeend of the body :to obstruct back draft from the chimney.

1. In a draft appliance for furnaces, a hollow body 'member for delivering the products of combustion from a furnace to a chimney having its lower side cut away on downwardly and outwardly curving lines whereby to :provide a vbaflie extending beyond the discharge :end of the body to obstruct back draft from the chimney, and a vane extending beneath the said baffle and in the path of the products of combustion from the discharge end ofthe body audvconmma,

stituting means for dividing the products as they are delivered against the battle.

5. In a draft appliance for furnaces, a draft unit comprising a main flue having an upwardly extending branch, a diagonal flue section extending between the said fine and its branch and communicating at its ends therewith, a damper in the said flue, and a baffle unit comprising a hollow body in communication with the branch of the main flue and having a battle extending beyond its discharge end.

6. In a draft appliance for furnaces, a draft unit comprising a main flue having an upwardly extending branch, a diagonal flue section extending between the said flue and its branch and communicating at its ends therewith, a damper in the said flue, a battle unit comprising a hollow body in communication with the branch of the main flue and having a baflie extending beyond its discharge end, and a perpendicularly disposed vane extending beneath the said battle with its upper edge spaced therefrom.

7. In a draft appliance for furnaces, a draft unit comprising a main flue having an upwardly extending branch, a diagonal pipe section extending between the said flue and its branch and communicating at its ends therewith, a damper in the said main fine, a hollow cylindrical flue section in communication with the branch of the main flue having its under side cut away to provide a battle extending beyond its discharge end, and a vane supported beneath the battle and constituting means for dividing the products of combustion delivered from the discharge end of the said body and directed against the battle.

In testimony whereof I affix my signature.

FRANK B. SNYDER. [L.S.] 

